New species of mountain mouse deer in Horton Plains?

Walter Jayawardhana

COLOMBO: Reports by a wildlife photographer and a naturalist indicate that they may have either discovered a very rare new species or a sub species of a mountain mouse deer, known as Meeminna in Sinhalese, endemic to Sri Lanka.

The renowned wildlife photographer and specialist Gehan de Silva Wijeyratne and naturalist Nadeera Weerasinghe have for the first time encountered the alleged new species of the mammal in the Horton Plains National Park, the report said.

After the encounter the mouse deer was captured temporarily, photographed and its blood tested for DNA, before being released, the report indicated.

Meeminnas or mouse deer are the smallest variety of deer found both in wet and dry zone forests in Sri Lanka and is a miniature variety without the antlers of its more common cousins, and slightly bigger than a cat.

Before this, taxonomists have indicated that endemic to this region in Sri Lanka and South India there are three varieties of mouse deer live.

Out of the three, two are endemic to Sri Lanka. If the alleged find is conclusively accepted as a new species or a sub-species by the taxonomists, the scientific community, who classify living beings into groups, it would be the third kind of mouse deer found in Sri Lanka.

British taxonomist Colin Groves said in a paper published in June 2005 in the Raffles Bulletin of Zoology that three varieties of mouse deer lived in the South Asian region. The Indian mouse deer Moschiola Indica is endemic to the Eastern Ghats of India.

In Sri Lanka, the report said two varieties of Mouse Deer live. The White Spotted mouse deer Moschiola meeminna live in the dry zone and the Yellow Striped mouse deer Moschiola Kathygre live in the wet zone of Sri Lanka. Both species are endemic to Sri Lanka.

Both species raised the number of endemic mammals found in Sri Lanka to 18. The new species was encountered, the report said, while the photographer and naturalist were training Horton Plains National Park staffers in butterflies and dragon flies in February 2008.

The animal was discovered accidentally and in quite dramatic circumstances. Chased by a brown mongoose, third of its size, the alleged new species jumped into the water of a pond.

The report described how it was captured: “The mouse deer swam back to the far shore and faced off with the mongoose. The mongoose did not enter the water but at times approached within five to six feet of the mouse-deer which responded by flaring its throat and showing the white on its throat.

After fifteen minutes the mongoose seemed to tire of the chase and left. The mouse deer left but returned soon with the mongoose in pursuit and once again dived into the pond.

Forty five minutes later the duo left and Gehan de Silva Wijeyeratne and Nadeera Weerasinghe informed the park warden. Around 5 pm the mouse deer was seen again by the park warden and his staff. Later around 6pm it was taken in for safe custody, and offered no resistance. It had a small gash near the ear and was in an exhausted state.”

The report further said: “Given the significance of the live specimen, Gehan de Silva Wijeyeratne informed several scientists of the mouse deer being temporarily held captive. Two scientists took a blood sample for analysis.

Dr Tharaka Prasad the Deputy Director (Veterinary) of the Department of Wildlife Conservation and Dr. Prithiviraj Fernando who has worked on conservation genetics of elephants and other mammals, examined the mouse deer, which was released back into the wild later that day.

The mouse deer was found to be a pregnant female and measured 56 cm in length. This places it at the upper end of all specimens of mouse deer which have been measured.”

But the report did not rush to conclude whether the live specie they found was a new one or not. The report further said: “The newly split wet zone species is bigger than the species in the dry zone. It is too early to establish whether the mountain mouse deer is a separate species or a sub-species of the wet zone Yellow-striped mouse deer. It may even transpire that it has no distinct differences from the form found in the wet lowlands.

More work may need to be done to resolve the taxonomic questions by examining DNA from other specimens from the wet and dry zones. Ideally more measurements should also be taken in the field through a small mammal trapping survey in the field.” But the British taxonomist Colin Groves had already stated that ‘a single skull from Sri Lanka’s Hill Zone may prove to represent a fourth species’.